


Underswap Alphyne Sexploits

by CaitieLewd



Category: Undertale (Video Game)
Genre: Alphyne, Anal Sex, Begging, Consensual Sex, Enthusiastic Consent, F/F, Fucking Machines, Gags, Non-Consensual, Non-Consensual Bondage, Non-Consensual Oral Sex, Oral Sex, Rape/Non-con Elements, Self-Lubrication, Sex Machine, Solo, Teasing, Tentacle Rape, Tentacle Sex, Tentacles, Toys
Language: English
Status: Completed
Published: 2017-09-03
Updated: 2017-09-03
Packaged: 2018-12-23 11:57:26
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 2
Words: 5,074
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11989329
Author URL: https://archiveofourown.org/users/CaitieLewd/pseuds/CaitieLewd
Summary: Underswap Undyne and Alphys have a friendly disagreement regarding whether or not a machine can provide the same level of satisfaction as the "real deal." Undyne builds a machine to put her theory to the test.AUTHOR'S NOTE: Chapter 1 is consensual, chapter 2 is non-con.





	1. Working Out some Kinks

**Author's Note:**

> Hello! My name is CaitieLewd and this is my first smut fic! I originally wrote this as a part of the Kinktober event on Tumblr, but screw it it's my first fic so it's going up early. There is a follow-up to this which will be up shortly after this one. Starting in October I'll be putting the rest up as they come out, but for now enjoy these two teasers.
> 
> Also HUGE thanks to @ravvi here on AO3 (or ravvi-k on Tumblr). She is my sinpai who beta'd both of these stories and gave me lots of delicious tips and details to add. Thank you sinpai, I'm glad I done you proud <3
> 
> Some authors do their Kinktober fics as one multi-chaptered work, but since I have no other works at the moment I'll be doing most of them as their own works. Some may be short enough to put in a single drabble collection, but I think most of them will be separate. Plus that will make the tags easier to separate, because these are going to be ALL over the place. Fontcest, Tuffet, non-con, fisting, bondage...LOTS of crazy stuff. So enjoy! <3
> 
> OH, and before I forget: This was for Day 10 of Kinktober 2017. The prompts were Edgeplay, Gun Play, and Fucking Machine. I chose fucking machine :D

Confidence was something Undyne rarely felt, and smugness even less. But as she gazed upon her lover, she found herself overflowing with both.

Captain Alphys was seated several feet in front of her, completely naked, straddling what would best be described as a saddle made from soft, padded leather. A rope handle was attached to the front, and there were comfortable, leather stirrups Alphys had already slipped her clawed feet into. Undyne couldn't help but admire her for a moment, eyes tracing the Captain’s generous proportions that flowed over and hugged each and every curve of the machine. The soft, warm folds belied the strength that hid beneath—strength that Undyne was intimately aware of, and that the Captain knew how to use.

“Ahem? _Undyne?_ ” Alphys called, snapping the Royal Scientist out of her reverie. “Gettin’ a little cold here babe.” Her tail swished from one side to another. Nerves? Surely not, her girlfriend probably just couldn’t find a satisfactory place to settle.

“O-okay, w-we'll start slow and s-see.” Undyne stammered, then turned the red dial on the remote. Alphys felt the seat beneath her begin to vibrate. She grunted in surprise, but wasn't impressed just yet.

“Cute,” she said drily, tail coming to rest draped across the back of the saddle. This had all started with a minor argument between them regarding how effective machines could be at instigating sexual pleasure, at least compared to the real thing, so to speak. “It wiggles.” Alphys crossed her arms and rose a brow at Undyne in challenge.

“T-that’s not all it does,” Undyne grinned. Alphys started as something solid began prodding at her folds, giving the machine her full attention.

“Oh, okay,” she grumbled as the head of a warm, wet member began prodding at her opening. It thrust into her shallowly, just enough to move her folds aside before mechanically twisting left, right, and pulling away. Alphys held her composure, determined to prove some mindless machine wasn't enough to get her off, refusing to react as the gentle teasing went on for several minutes.

Without realizing it, the slow, persistent stimulation began to get to her. She could feel a wetness pooling between her legs that wasn’t from the lubricant on the shaft, and her hips had begun to grind into the saddle of their own volition. She forced herself to stop the second she noticed, sitting down hard on the seat with her hands curled into fists. The position only pushed her folds further apart, allowing the vibrations to run deeper and giving the shaft a better angle.

Undyne grinned widely as Alphys chewed her lip and flushed, then lifted the remote. “Ready for level two?” she asked.

“What’s level tw—whoa, whoa WHOA—!” Alphys shouted. The vibrations easily tripled in intensity, and without warning the shaft dove deep into her pussy, bottoming out near her cervix in one swift thrust. Alphys jerked and grunted, one hand reflexively flying toward the rope handle, stopping just short of grabbing it. The penetration was sudden, but not painful, not with how wet she was from all of that teasing. On the contrary, her pussy traitorously welcomed the false member, walls locking around the shaft hungrily. She gave Undyne her best scowl, struggling to keep her breaths even and hips from bucking into the deeply satisfying thrusts.

“Eh heh, heh...too much?” Undyne asked nervously. Alphys scoffed in response, pulling her hand back to cross her arms again, and resolutely staring at the wall behind her girlfriend. The shaft pulled out and thrust in again, going just as deep but much slower this time. Alphys could feel every ridge and vein molded into the length of silicone, and she couldn't stop the appreciative moan that escaped her lips. It continued to pump in and out at a torturously slow pace, providing just enough friction to work her up, and leaving her desperate for more.

With an impatient growl, Alphys ground her hips into the next upward thrust, which pressed her now exposed clit fully against the vibrating surface of the saddle. She inhaled sharply, almost pulling away from the shock before swaying lightly as a glorious warmth burst through her cunt and kept her firmly seated.

Undyne chose that moment to ratchet up the speed. The shaft began pumping faster, entering more shallowly and not completely pulling out before thrusting forward again. Alphys uncrossed her arms, but still refused to grab the handle. She held them held up in front of her, claws twitching with impatience. The quicker, shorter pumps were even worse than the slow ones, just enough to keep pushing her higher and higher, without enough to send her over the edge.

“Ok, now you’re just teasing me,” she growled, rocking her hips back and forth in the saddle in time to meet each pump. No matter how hard she tried, she couldn't get the member any further inside her. It was agonizing.

“F-fuck!” she panted, finally giving in and grabbing the rope handle with both hands. She stood up in the stirrups, thrust her tail in the air, then slammed her hips down onto the shaft, causing the whole machine to jolt. Undyne was glad she had equipped it with the high-grade shocks.

“Aaaaaaugh come ON!” she moaned, shamelessly rutting against the machine, yanking desperately on the handle to pull herself down even harder. Her thighs and ass slapped loudly against the supple leather, drenching the surface with sweat and slick. “Come on, Undyne, stop fucking with me!” she shouted.

Undyne’s own face was flushed now. The sound of Alphys’ pleasurable torment and the slap of her skin against the saddle was music to her ears. The sweat dripping from her face sparkled like diamonds. “You want more?” she asked, baiting her lover with her voice.

“Yes!”

Undyne grinned. “Are you sure?”

“YES come OOOOON!” Alphys cried, her voice jolting with the vibrations of the machine.

“I-I mean, it _is_ just a machine after all. All it’s going to do is _wiggle_ a little more…"

“FUCK, _YES!”_ Alphys begged, looking to her lover with repentant eyes. “Give it to me! Just give it ALL to me, PLEASE!”

“As you wish.” Undyne turned the dial to the maximum setting.

Alphys _screamed._ The vibrations became so intense her whole body shook. The shaft took off at a wild pace, the gears inside the machine revving into overdrive. The shaft pumped into Alphys’ pussy faster and deeper than ever, and the vibrations were a whole new world she was in no way prepared for. She’d _never_ experienced such brutally intense sex in her life. It was like a battle, and she had no clue if she was winning.

No, of COURSE she was winning. Alphys leaned forward and fucked the machine with all her strength, feet clenched in the stirrups, her knuckles turning white around the handle as she easily maneuvered her weight up and down. After an unbearably intense moment, she finally climaxed, slamming herself down in the seat one last time, with a triumphant shriek that quickly choked off into a soundless wail.

The shaft continued to pummel her mercilessly through the orgasm, pushing into her as her walls clenched down on the member so intensely that the sheer friction should have been painful. Instead Alphys felt only pure, insane bliss. The vibrations in the seat went straight through her clit and drew out the orgasm, sending out waves of pleasure which left her gasping, spasming, and completely wrung out.

Undyne slowly lowered the speed as Alphys came down from the high, watching as the reptile woman panting raggedly and sweat dripped down along her naked breasts. She waited until Alphys began to grimace with discomfort before finally bringing the machine to a stop. The shaft exited Alphys with a wet pop, and then retreated back to its hidden compartment inside the seat.

Undyne walked over to her. “Well?” she asked, her yellow eyes gleaming mischievously.

Alphys did her best to glare, but she still hadn't caught her breath, which rather ruined the intimidating effect. “Not… not bad,” she finally mumbled, her voice coming shakier than she expected. “Not bad at all.” She held out a hand to her lover, and Undyne offered her shoulder for support as Alphys stepped off the saddle. “Still a few kinks to work out, but I gotta admit, you might be onto somethin’, babe.”

Undyne giggled. “A f-few kinks indeed.”

After dismounting, Alphys used her other hand to grab Undyne’s face by the chin, turning it up to face her own. The move surprised Undyne, stilling her features. “Y’know, I think I’m ready for round two,” Alphys rumbled in her gentle but husky voice, so close to Undyne’s face that her hair fluttered with the words. “Except this time, I want something a bit more… what’s the word? Oh yeah, _organic._ Like a control test, because that’s how science is supposed to work, yeah?  Think you’ve got somethin’ like that around here, babe?”

Undyne gulped, the flush on her face returning even brighter. Her glasses slid down her nose a bit as she glanced away nervously. “U-uh, y-y-yes. I think I can a-arrange that…”


	2. ERROR 404: AFTERCARE NOT FOUND (non-con)

**Summary for the Chapter:**

> Underswap Undyne decides to build another sex machine after the first went over so well. She decides to test the prototype on herself. Things do not go as planned.
> 
> This was for day 12 of Kinktober 2017. The prompts were Master/Slave, Tentacles, or Hand-Jobs. I chose tentacles >:3
> 
> WARNING: NON-CON AHEAD

Undyne entered the sterile, white lab nervously and shut the door behind her. The room was small, more of a large storage closet than a lab. But the newly-installed, white tiles covering the walls and floor created the illusion that the space was surprisingly large and open. Taking a deep breath, Undyne stepped into the center of the room and turned to face the door. She was wearing no clothes, as the nature of her task required it. Though she was completely alone, she crossed her arms over her chest in some semi-conscious attempt at modesty. It just didn't feel right, being naked in what was technically her workplace.

Well, not  _ technically  _ her work-space. Not anymore. After her previous gift to Captain Alphys had gone over so well, Undyne’s mind had scrambled to dream up even more possibilities. Then some particularly...inspiring, anime DVDs had turned up in the dump, and she knew what she was going to make next.

After dusting off a few projects she'd already completed to keep the queen happy for a while, she’d locked herself in her basement lab for two weeks. She’d designed, sculpted, molded, welded, and coded. And during her scant hours of free time, she did inexhaustible “research.” Research which had been lovingly archived in digital form and now took up an inordinate portion of her servers.

All of that effort had culminated in this machine. It was still only a prototype, and she needed to run a brief test before showing it off to her girlfriend to remove any kinks in the programming. Well, the right ones, anyway.

Undyne tucked a lock of hair that had fallen out of her bun behind a gill, then spoke quietly. “Begin automatic cycle, level one.”

A simulated feminine voice echoed from all around in the crisp, disinterested tone of an AI. “Activate: automatic cycle, level one.”

The room filled with the hum and whirr of mechanical servos, and six tiles in the floor around her opened up and revealed ominously dark holes. After a brief second, several red tentacles uncoiled from the holes, and lazily flexed themselves like they’d been woken from a nap. Most were about the width of Undyne’s arm, though some were thicker than others, intended for support and restraint during the later phases. Each was tapered near the end and adorned from tip to bottom with hundreds of pinkish, fingertip-sized suckers.

The half-dozen tentacles immediately oriented themselves around Undyne, bobbing and weaving in a seductive, snake-like dance. They glistened all over with a clear lubricant, another invention of her design. When one experimentally leaned within her reach, she put out a hand and stroked it fondly, smearing the substance over her hand. The fluid was the perfect consistency, slick, but not watery or oily. As she watched, tiny beads of liquid spread back over the skin of the tentacle where her fingers had wiped it away, automatically replenished through microscopic pores in the tentacle’s artificial membrane.

The lubricant left a tantalizingly cool tingle on Undyne's fingers. “Perfect,” she whispered, unable to resist putting two small dabs on her nipples. The small nubs immediately contracted and hardened. A shiver ran up her spine, and she flushed at how quickly she’d gotten comfortable with this. Boldened, she licked the remainder off her fingers, savoring the cool, minty taste and the sensation it left on her tongue. It  _ was _ edible; and besides, she told herself, it was good to know whether or not the membrane affected the flavor.

Undyne licked her lips, further spreading the tingle as she eyed her creation with nervous excitement. “Mmmm...okay. Begin level two.”

“Now entering level two,” the AI confirmed.

New holes opened up in the walls and more tentacles emerged, doubling the original number. The writhing collective reached out to Undyne, slithering together to form a seat, then gently scooping her off the ground. A couple of tentacles wrapped around her torso for extra support, and another two snaked up her legs, twisting around a few times to ensure they had a good grip.  Everywhere they touched became lightly coated with lubricant, which was the reason Undyne had gone in nude. The fluid would have utterly ruined her clothes

“Oooooh,” she breathed, shivering in the impromptu chair. The scarlet appendages were delightfully warm, which made their slick, firm hold feel even more alive and alien. Every place they touched became coated in the stimulating lubricant, inducing gooseflesh that prickled over her in waves. A blush crept onto her face. This was going...well, she thought to herself. Wow.  _ Yes _ . Good job, Undyne.

One of the tentacles wrapped around her legs had slithered its way up to her slit, and tickled playfully at the opening. “O-oh!” Undyne cried, face flushing as she giggled coyly. Yes, level two was doing  _ very  _ well. The adaptive AI was already learning, figuring out what behaviors best matched the situation.

“Okay, o-okay,” she stammered, suddenly finding herself short of breath. “T-that's quite enough for n-now. Program: terminate.”

The hum of machinery kicked in again. “Now entering level three,” the AI announced. The lights in the room dimmed ominously.

“Wait, wha—” The tentacles contracted, squeezing the wind out of her for a second. They lifted the small woman even higher into the air, her slight frame no trouble for the high-powered hydraulics.

The tentacle by her slit became bolder, nudging her folds aside and prodding at her entrance insistently. Undyne gasped, and not just out of the need to fill her starving lungs. Her pussy was dry, but the lubricant allowed it to enter freely as it made light, shallow movements that each went a little deeper than the last and coated the sensitive folds between her legs with the tingling stimulants. It was intrusive and not AT ALL what the machine should be doing after she’d told it to stop, but...

No, she couldn’t show that this was getting to her or the AI would just keep going. Undyne swallowed and took a deep breath through her gills, and let it out through her mouth. Resolutely, she held completely still except for the slight tremble in her limbs. Phase three wasn’t so bad, and it was the last one she had set into this particular cycle. She could still use the failsafe command, but she was still trapped in the mechanical tentacles’ grip a good six feet from the floor. The consequences of using a forced shutdown while she was up here were unappealing.

As though sensing that something was amiss, a couple of smaller tentacles began winding around her small, firm breasts. Their probelike tips traced circles around her areolas, slowly spiralling inward until they found the nubs in the centers. They flicked them playfully, then caressed them with a feather-soft touch, bringing light tugs of suction as the suckers latched on and released.

“A-ah, aaaaah...oooh…” Undyne squirmed, trying to stay focused on her predicament. Clearly the AI had seen what she’d done with her nipples before and was replicating that. Adapting to what it knew she liked. As it should. This was all part of its programming.

But the tender ministrations being plied to her body and the cool prickle spreading into her most sensitive areas were awakening the darker parts of Undyne’s mind, and she was slowly growing unsure that she wanted any of this to stop. Her pupils dilated, her face flushed a deep purple-red and her gills fluttered as she struggled to control her breathing. She felt her legs fall open. Her body relaxed and reclined back, surrendering to the appendages as they worshipped and indulged themselves on her most sensitive, intimate areas...

“Now entering: experimental phase, level four.”

Undyne jolted upright with a gasp, sweat pouring down her face as she struggled to focus. The lights dimmed again, and over a dozen more tentacles of all shapes and sizes burst out of the floor, walls, and ceiling. They snatched Undyne’s wrists and ankles, yanked her out of the suspended throne, then pulled all of her limbs apart into a prone, spread-eagle position.

Undyne reeled, her mind racing to comprehend what was happening as the touches rapidly turned from seductive to invasive. Level  _ four? _ She hadn’t finished it yet, the sequence shouldn't have even be able to run. Unless...unless the AI was looking for more ways to adapt. Creating its own sequence of events. But, where would it find the data samples? The AI was smart, but it wasn't designed to invent behaviors out of thin air. It could only analyze recordings of sample behaviors,  _ then _ use those parts to build sequences.

Unless…

It  _ did  _ find some data samples.

Terabytes of them.

_ Zettabytes. _

Research compiled over weeks of diligent hunting, all conveniently archived on another drive, connected to the same computer network.

Oh... _ fuck. _

Undyne panicked. She pulled and thrashed, desperately hoping the lubricant would help her escape the coiling grasp. Instead the fluid only strengthened the grip of the suckers on her soft, smooth skin, giving the machine more purchase as it held her firmly in place. Oh  _ why _ had she made them so anatomically accurate?!

Enough, that was enough. She could deal with a broken arm if the tentacles dumped her on the floor, she wanted this to end. “S-safeword!” she rasped. “Safewo—ghhk!” One particularly fat tentacle plunged into her mouth, cutting the plea into a garbled choke. She gagged, trying to pull away as she screamed the command again. The word came out as a muffled warble, and the attempt gave the tentacle more room to thrust deeper as it writhed and wrestled with her tongue

The violation of her mouth had drawn all of Undyne’s attention away from the tentacle still hovering near her pussy, until the member abruptly hardened and dove deep inside her without warning. “MMMPH, nnh!” she protested, writhing as her walls clenched painfully around the a savage entry.

“Hnnghhh,” she whimpered as the tentacle worked itself in like a living thing. Its girth slowly grew as it went, stretching her cunt wider and wider as it squeezed inside until it hit her cervix like a punch to the gut. Undyne’s throat tightened, and tears pricked as her abused body went slack, no longer resisting the too-large intrusion as a few of the spare tentacles began to snake around her torso and legs, fondling her again her with renewed vigor.

With nowhere further to go, the member in her cunt  _ twisted, _ thickly coating her entire passage with the stimulating lubricant. 

“Hmmmmm, hhnf, hnn!” She whined around the gag as her entire body twitched. It felt as though thousands of sharp, cold barbs were nettling her from the inside. Rows upon rows of suckers fastened to her inner folds, resisting and pulling as the member leisurely completed a single revolution, leaving her gasping for breath. She could barely get enough air around the slimy gag, already dripping with long strands of saliva and lubricant, and the constant stimulation from all sides was suddenly far, too much for her to handle. With a low whimper, she pulled her knees and elbows together, attempting to enter a fetal position.

The mass of tentacles responded by sending two more limbs to wrap around her knees and wrench them apart, holding Undyne as open as her limber body would allow. The tentacle in her pussy pulled nearly all the way out, then drove in again, and again, and again, fucking her at a punishing pace.

“Hhhhf, nnnh, mmmmm!” she cried, struggling as her vaginal walls painfully resisted the invasive member. The AI never slowed, never paused or gave her a moment to breathe as it ravaged her pitilessly. The other tentacles did nothing to ease her pain, squeezing and coiling along every inch of exposed skin until her entire body was painted with clear, prickling fluid.

At some point during the tireless pummeling, Undyne’s body started to betray her. Her walls wrapped around the intrusion, reluctantly taking it bit by bit. Her screams and cries tapered off into moans and whimpers. She struggled, shaking her head furiously, fighting the warmth pulsing deep inside her. She was close, she was  _ so _ close, and she clung to the thought like a lifeline. The AI was programmed to never give up until the subject had been satisfied, so if she could just come, it would stop and let her go. Tears of frustration poured down her face, dripping into the strands of hair hanging below her.

Out of nowhere the member twisted sharply as it entered, curling back the other way as it pulled back out. Undyne jolted, the abrupt change sending an urgent bolt of need through her cunt. It took only a few spinning pumps to send her crashing over the edge. She squealed as her entire body tensed, trembling as the restraints held her fast. Her pussy clamped down on the member as one of the most intense orgasms of her life ripped through her, body and SOUL.

When the peak abated her small body went limp. It was all Undyne could do to gasp for air around the gagging limb. Her tears were indistinguishable from the saliva and lubricant flowing freely down her face. The member slipped out of her body with a slick pop to hang limp below her entrance, drenched with Undyne’s fluids and quietly dripping into a pool on the no-longer pristine floor below.

The limbs continued to hold her captive as she caught her breath, shaking off the aftereffects of the climax. There, it was over. The AI had “satisfied” her. Now it would let her down and begin the aftercare sequence.

The lights in the room went red.

“Now entering experimental phase: Finale”

“Mmmmph?!” Undyne spluttered. The tentacles lurched back to life. The one below her pussy plunged back in, brutally raping her once more. The members in her mouth and her cunt drove in together, filling her. They coiled and spun, literally drilling Undyne from both ends.

The single-minded mob of limbs claimed the rest of her body, snaking around her torso, groping her breasts, circling and constricting her arms and legs. A couple toyed with her breasts, pressing their suckers down on her nubs and ripping them away with a chorus of wet snaps. A few small tendrils wrapped around her fingers, wormed between her toes. It was as though they were striving to leave no part of her body untouched, no gap unfilled. Her entire body was soaked, glistening with lubricant, but she couldn’t feel it over the sensation of two dozen tentacles molesting her.

Undyne wept, gargling around the limb in her mouth, begging it to stop. All that escaped her lips were streaks of spittle and garbled nonsense. Make it stop, make it stop, make it...

She started as a lone, thick member inquisitively probed her ass—her only opening which hadn’t been filled. Undyne squirmed and thrashed like she’d been shot. She shouted in denial, shaking her head, heaving against the imprisoning limbs until she thought her own might break.

It didn’t stop. Nothing could stop it. Even the other limbs fucking her gave pause, giving the new member the chance to join. It snaked its way along her gluteal cleft, the small tapered tip meeting no resistance until it found her her tight, clenched hole. Mercilessly, it began to worm its way inside, moving in short, sharp jabs like a too-large cork shoving its way into a bottle.

“Mmmm...hhhhf...mmmnn...n-NGH—!” Undyne convulsed, ass stinging as the tip penetrated her sphincter. The way having been opened, several more inches of the member plunged in after, bottoming out somewhere in her lower gut and forcing her wide open to accommodate it’s girth. If Undyne had been looking, she could have seen the limb distending her stomach.

“Mmm, hnn, nnn, hhff, hnnn...” Each breath she took only added more pressure, more pain. Tears streamed down her face. It was too big, she was too  _ full _ . It was splitting her in half, and something was going to burst if it didn’t...

The AI decided that Undyne was now prepared for the finale. The member in her ass twisted in her gut, coating her passage with the lubricant. It irritated and stung the stretched and inflamed flesh, making the space between her legs throb in time with her heartbeat.

The member stopped moving, and Undyne tensed. She knew what was coming next.

The tentacle pulled almost all the way out, and with no more preamble pillaged her depths with all the tireless precision one could expect from cold gears and silicone. It took off at a sadistic speed, not even trying to ease her in. The tentacles in her mouth and pussy resumed fucking her as well, working in tandem until the three found a rhythm, the one in her ass pulling out just as the ones in her pussy and mouth thrust in, and then plunging back in when they came out. The force of the thrusts sent Undyne’s small body jerking back and forth like a rag doll. The other tentacles wrapped around her body squeezed tighter, holding her still and forcing her to take the full brunt of their ruination. Too much, too much....

Undyne sobbed, breath coming in short, shallow pants that barely gave her enough air to stay conscious. She had to cum again. It was the only way the machine would stop. But how was she supposed to get off to this? It was torture. But she had to, she  _ had _ to.

She wiggled her hips a bit, then hissed as that only caused the limb in her ass to go in at an off angle. She tried closing her eyes, forcing her tense body to relax. She allowed the members to take her without resistance, offering herself to their cruel devices.

The ravaging went on and on for five, ten, fifteen minutes. She had never felt so degraded, so full, so  _ violated _ . Every orifice was stuffed to bulging, every crevasse of her body was dripping with lubricant and her own cum.

And yet, despite how vile Undyne felt, something warm and urgent was winding up in her again, pulsing in her cunt, her ass, her  _ SOUL.  _ She forced herself to think about why this depraved idea even appealed to her in the first place. Huge, flexible members all around her. Holding, caressing, massaging, programmed to bring her pleasure by any means necessary. Completely unable to escape, unable to stop the pleasure...

Her cunt throbbed and Undyne gave a long, desperate moan. The tentacles sensed her impending climax, and changed the rhythm once more. All three members pulled out together, then drove in all at once, jolting her whole body, punching out a terrified squawk. Droplets of fluids splattered in every direction.

“Mmmmmggh, uuuuuff, nnnnaaahhn…” Undyne warbled incoherently behind the gag, growing louder each time the members they hilted themselves. They brought her higher, higher, so much higher than she should be when in such anguish. She closed her eyes and shook her head violently. Please,  _ please _ just let her cum. Let it end, let this unremitting nightmare end—!

Undyne came with an unearthly shriek. The tentacles skewed her with one last thrust, fluid gushing around them and running down her legs. She couldn’t hear the mechanisms grinding and straining to hold her still through the torturous rapture.

Surges of immaculate pleasure and agony rocked Undyne in waves. A small part of her fully expected to pass out. Surely her body couldn’t handle this, surely this was too much,  _ nothing  _ could tolerate this amount of stimulation.

After nearly a full minute of wailing and spasming, the insanity slowly let Undyne escape its grasp. It was replaced by a deep exhaustion she felt in the very depths of her SOUL

“Now exiting: experimental phase, Finale,” the AI announced. The tentacle in Undyne’s mouth withdrew with a wet squelch.

“...fi-leeh…” she croaked, unable to move her battered tongue or jaw properly. She moaned when the members in her pussy and ass pulled out, unceremoniously exiting her without any care or finesse.

The tentacles around her body unwound themselves, then gently lowered Undyne to the ground. They took extra care with her head as they laid her right in a pool of her own fluids and excess lubricant, some of which was still leaking out of her. Most of her hair had escaped her bun, sticking to her shoulders and back. A sopping lock fell across one of her eyes, leaving half of her vision in darkness. Undyne was too drained to even think of moving it.

Her eyes drifted shut, a desperately needed sleep slowly taking her. She yawned, wincing as her jaw twinged with pain. Between her mouth and her lower regions, Undyne now felt strangely empty and...stretched. Her insides felt as though they’d been widened and opened up, leaving everything between her legs permanently disfigured. Her eyebrows stitched together as she trembled, tears dripping down her face. She wondered if Alphys would notice. She wondered if she would ever return to...normal.

The AI sounded off one last time. Undyne almost jumped out of her skin.

“Final phase ‘Aftercare’ not properly installed. Please consult system administrator for further assistance.”

**Notes for the Chapter:**

> You know it's funny, I've never really sought out any Alphyne smut, much less Underswap Alphyne. But when these two stories came to me they just SCREAMED to be finished first. I'm thinking it was the breasts. Man do I love boobs. And nipples. If that wasn't clear by the nipple action in there, haha.
> 
> There ARE actually tingly lubricants out there. And they are really quite nice, if you like cooling or tingly sensations.
> 
> Again here is my Tumblr, if you want to stop by <3 https://caitielewd.tumblr.com/

**Author's Note:**

> The machine in this fic is basically a sybian and fucking machine all in one. If you don't know what a sybian is PLEASE look it up. Holy shit I dream of being tied to one of those. *Ahem* sorry that got a bit crude, what was I doing again? Oh yeah writing porn.
> 
> OH and here is my Tumblr, give it a look if you like :3 TW for non-con/dub-con art that will probably be up there:
> 
> https://caitielewd.tumblr.com/


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